Abstract Details
| Name: Hariharan Krishnan Affiliation: NCRA-TIFR, Pune Conference ID: ASI2019_44 Title : Study of Fine Structures in Solar Radio Emission Authors and Co-Authors : Hariharan Krishnan Abstract Type : Oral Abstract Category : Sun and the Solar System Abstract : Solar radio emission an be broadly categorized as : i) continuum emission and ii) transient emission. The former is composed of a non-variable stationary component considered to be due to the free-free emission from the inherent electron distribution in the corona and a “slowly-varying” component due to the extreme density condensations above “Active Regions”. At times the radio emission from the Sun can be impulsive in nature and are often referred as “radio bursts”. The solar radio bursts are often identified and classified based on their spectro-temporal characteristics seen in the frequency-time plane. These transient phenomena are observed to occur over a broad range of frequencies from a few kHz up to a few GHz, and show very high brightness temperatures in the range 10^12 -10^14 K. The impulsive radiation is often associated with the solar transients, viz. Flares, Coronal Mass Ejections (CMEs), etc. which are the consequences of large scale magnetic energy releases that take place on the Sun. With the advent of digital technology and improved radio instrumentation techniques the next generation of very sensitive radio telescopes offer the capability of spectroscopic imaging observations covering many octaves of the radio frequency band with very high spectral and temporal resolution. This has paved way for in-depth studies of weak and fragmented emission features in the solar radio radiation particularly during the solar minimum period. Detailed observational studies of such phenomenon give us a better understanding of coronal physics. High sensitivity radio telescopes (viz. LWA1, LOFAR, uGMRT, MWA, MUSER) with wide instantaneous bandwidth at high spectro-temporal and angular resolutions are ideal for such observational studies, particularly during periods of low solar activity. In this talk, I will describe some of our recent high “resolution” observations of fragmented radio emission from the Sun and their usefulness in understanding the solar corona. |